▎ 摘　　要

NOVELTY - Preparing graphene-modified copper-based electrical contact material based on in-situ synthesis comprises (i) using polyethylene glycol or polyvinyl alcohol as solid polymer carbon source, and dissolving the solid polymer carbon source in alcohol to form homogeneous mixed solution, preferably the dissolution temperature is 20-80 degrees C, (ii) fully stirring the copper powder in the homogeneous mixed solution, filtering the copper powder in the solution and drying, coating the surface of the copper powder with polymer layer of polyethylene glycol or polyvinyl alcohol to obtain a copper powder coated with a polymer layer, heating the copper powder coated with the polymer layer and calcining in high-temperature heating furnace at 500-1050 degrees C for 0.5-2 hours, the heated shielding gas is a mixed gas of hydrogen and argon, and converting polyethylene glycol or polyvinyl alcohol on the surface of the copper powder into graphene in a protective gas. USE - The method is useful for preparing graphene-modified copper-based electrical contact material based on in-situ synthesis. ADVANTAGE - The method: introduces graphene reinforcement into a copper-based electrical contact material by an in-situ chemical vapor deposition process, which greatly saves the cost of the graphene raw material and solves the process problem of uniform dispersion of graphene in the copper matrix; and significantly enhances the mechanical strength and arc ablation resistance of the contact material without reducing the conductive and thermal conductivity of the contact material. DETAILED DESCRIPTION - Preparing graphene-modified copper-based electrical contact material based on in-situ synthesis comprises (i) using polyethylene glycol or polyvinyl alcohol as solid polymer carbon source, and dissolving the solid polymer carbon source in alcohol to form homogeneous mixed solution, preferably the dissolution temperature is 20-80 degrees C, (ii) fully stirring the copper powder in the homogeneous mixed solution, filtering the copper powder in the solution and drying, coating the surface of the copper powder with polymer layer of polyethylene glycol or polyvinyl alcohol to obtain a copper powder coated with a polymer layer, heating the copper powder coated with the polymer layer and calcining in high-temperature heating furnace at 500-1050 degrees C for 0.5-2 hours, the heated shielding gas is a mixed gas of hydrogen and argon, and converting polyethylene glycol or polyvinyl alcohol on the surface of the copper powder into graphene in a protective gas, where the copper powder is dendritic copper powder, (iii) placing graphene-coated copper powder, copper zirconium alloy powder, copper lanthanum alloy powder and hydroxyzinc stannate powder in a ball milling device for ball milling, deforming the dendritic copper powder into flake copper powder after ball milling, where the graphene wrapped between the branches of the dendritic copper powder is inside the flake copper powder, the extension causes the surface of the copper powder to be covered by the graphene-free portion, the copper powder not covered by the graphene has good sintering formability, and after mechanical ball milling, the graphene and the copper matrix are better integrated into one body, and improves the interface bonding strength, and (iv) placing ball-milled copper powder of graphene, copper-zirconium alloy powder, copper lanthanum alloy powder and hydroxyzinc stannate powder in a into the sheath molding green body for cold isostatic pressing, sintering the shaped body at high temperature to obtain a sintered body of the electrical contact, where the sintering atmosphere is an inert atmosphere of nitrogen or argon, the cold isostatic pressing pressure is 250-300 MPa and the high temperature sintering temperature is 900-950 degrees C, heating the sintered compact and subjecting to hot extrusion deformation, and obtaining the graphene-modified copper-based electrical contact material by cold rolling deformation.